Method of dispersing reaction of organosilane and polyolefin

ABSTRACT

A method of dispersing polyolefins in water and a resulting product useful as a coating material for glass fibers. Glass fibers coated with the products and mixed with polyolefin molding resins produce molded parts having increased strength. The polyolefin material is combined with an organosilane and the combination is then mixed with a water dispersible polyester material which acts as a carrier for the polyolefin-silane material during a subsequent emulsification or dispersing operation.

United States Patent Preston [54] METHOD OF DISPERSING REACTION 0FORGANOSILANE AND POLYOLEFIN inventor: Jerome A. Preston, Fort Wayne,1nd. Assignee: Owens-Coming Flberglas Corporation Filed: Dec. 5, 1968Appl. No.2 781,618

U.S.Cl. ..117/126GS, ll7/l26GB, 1l7/l00 S, 260/827, 260/29.4 M, 260/29.6R, 264/112,

Int. Cl. ..C03c 25/02 Field of Search ..260/827, 29.4 M, 29.6 R; 117/126GR, 126 GS, 72, 27, 100 S; 264/112, 143

References Cited UNITED STATES PATENTS 5] Feb. 22, 1972 3,159,60012/1964 Watkins ..ll7/126X 3,505,279 4/1970 Preston et al. ..260/827XPrimary Examiner-William D. Martin Assistant Examiner-D. CohenAttorney-Staeiin & Overman [57] ABSTRACT 9 Claims, No Drawings METHOD OFDISPERSING REACTION OF ORGANOSILANE AND POLYOLEFIN BACKGROUND OF THEINVENTION The present invention relates to the use of polyolefin resinsboth as coatings and as molding compounds. A preferred reinforcement formolding compounds is glass fibers and a problem has existed in the priorart in producing a good bond between the polyolefin resin and the glassfibers.

The glass fibers which are used for reinforcing resins are produced byattenuating streams of molten glass into tiny monofilaments which aregathered together into a strand which is being advanced at about 10,000feet per minute and wrapped around a revolving drum. The glass fibersare easily scratched when pulled over guide surfaces or when rubbedagainst each other as the fibers are gathered into a strand or when astrand is flexed during processing or use. In order to protect thefibers, it is necessary to apply a lubricous film to the attenuatedfilaments before they are brought together into a strand and are wrappedaround the drum. ln the usual commercial operation, an aqueous solutionof a film former is used for this purpose and the resulting coiledpackages are then dried to leave a protecting coating on the filaments.In some instances, organic solutions of film formers have been used.Organic solvents are expensive, however, and create an explosion hazardinasmuch as they are applied to the fibers at a location adjacent hightemperature and high voltage equipment.

An object of the present invention is the provision of a new andimproved method for dispersing a polyolefin in water.

A further object of the invention is the provision of a new and improvedmethod of strongly attaching polyolefin-molding resins to glass fibers.

SUMMARY According to the present invention, polyolefins are madedispersible in water by first combining them with an organosilane andthereafter incorporating the combination into a water dispersiblepolyester resin. The water dispersible polyester resin acts as a carrierfor the polyolefin-organosilane material. The polyester is miscible andsolvates with the polyolefin-organosilane material, and as the polyesteris dispersed into the water, it carries along with it the polyolefinmaterial that is desired to be dispersed in the water. The polyestermaterial performs another function in that it separates the silaneportions of adjacent molecules to greatly retard cross-linking of thesilane materials in the aqueous media. The polyester material iscompatible with both the polyolefin portion and the organosilane portionas is necessary to perform both of the above functions. lt appears thatthe long chain fatty acid portion of the polyester molecule iscompatible with and solvates the polyolefin desired to be dispersed,while carboxyl groups of the polyester resin have afiinity for thesilane material particularly when hydrolyzed. Polyester materials aremade dispersible by incorporating surface active agents therewith, andthe polyester in turn carries the polyolefin-organosilane material alongwith it as the polyester is emulsified. The organosilane in addition toaiding in the process of dispersing the polyolefin, performs theadditional function of providing an attachment to the surface of theglass fibers.

it is not necessary for the polyester material to be chemically combinedwith the polyolefin-organosilane material while the materials are in thewater dispersed phase. When the polyester material is not so combined,the organosilane has greater mobility and can better coat the surface ofthe glass fibers in a preferred somewhat laminated orientation.Polyester materials when in a chemically uncombined state, surround thepolyolefin backbone molecules which project outwardly from theorganosilane material. With this arrangement, later applied impregnatingpolyolefin-molding resins can chemically combine directly with thepolyolefin backbone material that is attached to the silane. In thoseinstances where polyester material is not chemically combined with thepolyolefin-organosilane material, it may be displaced to some degree bythe laminating resin during the molding process. Where this displacementof the polyester is desired, the polyester material is preferably anon-cross-linking saturated polyester. In most instances, however, anincrease in strength is obtained by using an unsaturated polyestermaterial which can chemically combine with the polyolefin-laminatingresin,

DESCRIPTION OF THE PREFERRED EMBODIMENTS A polyolefin is made waterdispersible by means of the following procedure:

EXAMPLE 1 Two hundred and forty grams of a polypropylene resin having amolecular weight of approximately 2,000 and containing some unsaturatedbonds was mixed with 2,400 cc. of xylene at room temperature. Themixture was heated with continual stirring to a temperature of 300 F. tocompletely dissolve the polypropylene material. In a separate vessel, 14grams of benzoyl peroxide were mixed with 1,000 cc. of a 15 percent byweight solution of gamma-aminopropyltriethoxysilane in xylene solvent.The silane and peroxide are mixed at room temperature and are thereafterslowly added to the polypropylene solution with continual stirring whileat 300 F. The materials are cooked for approximately 1 hour at 300 F.following which the materials are poured into cooling pans to a depth ofapproximately 1 inch. The pans are cooled to room temperature and driedfor 24 hours at 70 F. to reduce the solvent to a level of approximately15 percent by weight. The material is then ground in a hammermill untilall of the material passes through an 18 mesh screen.

A polyester resin is made using the usual procedures well known in theart by cooking 1 mole of phthalic anhydride, 1 mole of maleic anhydride,and 2.04 moles of propylene glycol to a molecular weight ofapproximately l,200. This polyester resin is then thinned to a syrupymaterial by mixing 70 parts of the resin with 30 parts of styrene.Ninety parts of the polyester resin syrup is mixed with l0 parts of thepolypropylene-organosilane powder prepared as above described, and thismixture is thoroughly blended for 1 hour to produce what is hereinaftercalled dispersible resin blend.

An aqueous dispersion of the dispersible resin blend of the followingcomposition is prepared:

Materials Percent by Weight Dispersible resin blend 20.0% EmulphorTEL-719 nonionic emulsifier (polyoxyethylated vegetable oil) 0.25%Triton X- ncnionic emulsifier (lsooctyl phenylpolyelhoxy ethanol) 0.25%lgepal C0-2l0 nonionic emulsifier (Nonylphenoxypoly (ethyleneoxy)ethanol) 0.25% Water (deionized) Balance The water dispersion isprepared by adding the emulsifying agents to the dispersible resin blendand thoroughly mixing for 10 minutes. Approximately one-fourth of thewater is thereafter added to the mixer in small amounts until theinversion point is reached. After the inversion point is reached, it ismixed slowly for approximately 5 minutes, following which this mixtureis added to one-half of the water contained in a mix tank. After thematerials are thoroughly mixed in the mix tank, the remainder of thewater is added to complete the preparation of the resin emulsion. Thispercent solids emulsion is applied to glass fibers at forming using astandard graphite roll type applicator over which the fibers are drawn.After being wetted by the emulsion, the fibers are drawn together into a408 monofilament strand which is then wound into a package and dried.The fibers so produced have a coating thereon which comprisesapproximately 3.65 percent by weight of the coated strand. The coatedstrands are chopped into approximately one-quarter inch lengths. Twentyparts of these coated short fibers are then placed in a drum tumblerwith 80 parts of an isotactic polypropylene having a melting index of5.5 and a molecular weight of approximately 200,000. This mixture isthen placed in a 1 inch National Rubber Machine Screw Extruder which iselectrically heated to 500 F. and the mixture is extruded into aone-quarter inch diameter cylindrical rod which is then fed into aCumberland Pelletizer to form lt-inch long pellets. The pellets are inturn fed to an injection molding machine heated to 500 F. and thematerial is extruded into a standard ASTM D638 dog bone test specimen,which when cooled at room temperature and tested in a standard tensiletesting machine, broke when a force equal to 6,970 square pounds perinch was applied to the specimen. The material also has a modulus of471,000 pounds. These results are tabulated as tests l-A in thefollowing table. The process was repeated using different blends of thecoated glass fibers and of the isotacticpolypropylene resin and theirstrengths are recorded as tests l-B through l-F in the following table:

TABLE 1 Tensile Strand Percent Strength Solids Glass p.s.i. Modulus l-A3.82 20.] 6,970 471M l-B 3.82 20.3 8,080 531M l-C 3.82 20.1 9,020 697Ml-D 3.82 17.8 10,470 867M MS 3.82 38.0 11,300 1060M l-F 3.82 [8.2 9,555829M l-G 2.06 20.7 5,990 855M 2-H 2.92 18.0 7,880 518M Z-l 2.92 20.l8,220 537M 2-J 2.92 22.2 8,800 524M 2-K 3.52 2!.0 9.070 671M By way ofcomparison, the process given above was repeated using a coated glassthe coating of which did not contain the polypropylene-organosilanematerial. in its place, the glass was coated with an aqueous solutioncontaining 0.4 percent of glycidoxypropyltriethoxysilane, 12.0 percentof the same polyester material given above, and the same percentages ofthe surfactants used above. Dog bone samples were made using this coatedglass to give specimens having 20.7 percent glass and a tensile strengthof 5,990 p.s.i. Properties of the material described in this paragraphare given as l'G in the above table.

EXAMPLE 2 The process of Example 1 was repeated excepting that onepercent by weight of a material made by reacting 13.7 parts ofgammaaminopropyltriethoxysilane and 16.9 parts of polyethylenimine(Montrek l2), and 0.25 percent of glacial acetic acid are added to theemulsion that was used to coat the fibers. The coated fibers had acoating of 2.92 percent by weight of the coated fiber, and a dog bonesample having 18 percent of glass fibers therein, had a tensile strengthof 7,880 p.s.i. This material is listed as 2-H in Table 1 above.

The process of Example 2 was repeated to make a sample comprising 20.1percent by weight of glass, and its result is given as test 2-l of Table1.

The process was also repeated preparing a sample having 22.2 percent ofglass by weight, and its result is given as test 2- J in Table 1 above.

The process of Example 2 was further repeated excepting that the coatedglass fibers of Example 2 were given a second coating of the resinemulsion before they were chopped into one-quarter inch lengths. Theglass fibers had a resin coating comprising 3.52 percent by weight ofthe coated strand, and dog bone samples containing 21.0 percent byweight of this double-coated strand had a tensile strength of 9,070p.s.i. The results of this material are given as test 2-K in Table 1above.

In the above reaction between the gamma amino propyltriethoxy silane andthe polyethylenimine, the imine ring is opened by the amino group of theorgano silane. The imine group is a very reactive group, and will reactwill substantially any type of organo functional group, as for example:an unsaturate group, an acid group, an acyl chloride group, an aminegroup, a hydroxyl group, a thio group, a halide group, etc., asdescribed in the publication entitled Ethylenimine, published by DowCorning Chemical Company, copyright 1965 or subsequent edition.

The polyethylenimine-organosilane product, when acidified, containssubstituted ammonium groups which make the material soluble. Thismaterial is a solubilizin g aid, and the materials of Example 2 indicatethat other dispersible resinous materials can be added to thepolyolefin-organosilane materials in addition to the polyester materialto help disperse the material without harmfully affecting the resultingproperties of the finished molded material.

EXAMPLE 3 The procedure given for test l-A above was repeated exceptingthat Reactor Flake polyethylene having a molecular weight ofapproximately 200,000 was used as the molding resin in place of theisotactic polypropylene. Test specimens prepared using this moldingresin according to the procedure for test l-A above had a tensilestrength of 6,900 p.s.i.

By way of comparison, test specimens using the same polyethylene moldingresin when substituted in the test procedure given for test l-G abovehad a tensile strength of 5 ,900 p.s.i.

EXAMPLE 4 Any polyolefin which contains some reactive groups forcoupling with the organosilane can be dispersed in water using thetechniques of the present invention.

The process of test l-A was repeated excepting that (Microthene)polyethylene having a molecular weight of approximately l0,000 wassubstituted for the unsaturated polypropylene material that was coupledwith the organosilane for solubilizing. In addition, tertiary butylperoxide was substituted for the benzol peroxide in the production ofthe polyolefin-organosilane material. Test samples made in accordancewith the procedure of test l-A had a strength comparable to that of thematerial of test l-A. This test clearly indicates that any polyolefinmaterial can be dispersed in water using the techniques of the presentinvention to give good coupling between a polyolefin impregnating resinand glass fibers.

EXAMPLE 5 Any organosilane having functional groups thereon which can becoupled to the polyolefin material to be dispersed can be used topractice the techniques of the present invention. In addition to anamine group, the organosilane can have an unsaturated group, as forexample a vinyl or an acrylic group or an imine group. It can also havea silane hydrogen group, or any other group that can be linked to thepolyolefin. Suitable examples, although not limited thereto, are givenin Table l of the above identified related application Ser. No. 589,79l.By way of example, the process of l-A is repeated usinggammamethacryloxypropyltrimethoxysilane for thegammaaminopropyltriethoxysilane of Example 1. The material thus preparedis equally as water dispersible as that of test 1- A, and test specimensprepared therefrom have comparable strengths.

EXAMPLE 6 The procedure of test l-A is repeated excepting thatgammaglycidoxypropyltrimethoxysilane containing amine curing agent issubstituted for the garnmaaminopropyltriethoxysilane of test l-A. Thepolymer so prepared is equally as water dispersible as the material oftest l-A, and test specimens prepared using the glass fibers coated withthis material in accordance with the procedure of test l-A havecomparable tensile strength.

The polyolefin-organosilane combination product may comprise up toapproximately 50 percent, and preferably at least percent oforganosilane, and from approximately 50 percent to approximately 90percent of the polyolefin. The aqueous dispersible resin will comprisefrom approximately 5 percent to approximately 30 percent of thecombination product and from approximately 70 percent to approximately95 percent of the polyester. The aqueous dispersion may comprise thefollowing approximate percentages:

Dispersible resin 5% to 30% Surface active agents 0.5% to 3% Other watersoluble resin up to 5% Water balance The organosilane can react with thepolyolefin in one of two ways. In one type of reaction, a functionalgroup on the organo portion of the silane reacts with a remaining doublebond of the polyolefin; and in another type of reaction, silane hydrogenreacts with the double bond of the polyolefin. In the the following aregiven: vinyl silane, vinyltriethoxysilane, vinyldichlorosilane,vinyltrichlorosilane, divinyldichlorosilane, allyl silane,allyldichlorosilane, allyltrichlorosilane, diallydichlorosilane,allydifluorosilane, vinyldibromosilane, methoxyvinyldichlorosilane,dodecenylvinyldichlorosilane, didecenyldichlorosilane,didodecenyldifluorosilane, cyclohexenyltrichlorosilane,hexenylhexoxydichlorosilane, vinyl-tri-n-butoxysilane,hexenyltri-n-butoxysilane, allyldipentoxysilane, butenyldodecoxysilane,decenyldidecoxysilane, dodecenyldioctoxyfluorosilane,heptenyltriheptoxysilane, allyltripropoxysilane,vinyl-n-butoxydiiodosilane, divinylsilane, diallyldi-n'butoxysilane,pentenyltripropoxysilane, allyldi-n-butoxysilane, vinylethoxysilane,sec.-butenyltriethoxysilane 5-benzyl-6-(dinonoxysily)-l-hexene,4-phenyl-5-propoxydichlorosilyl)-l-pentene, 2- cyclopentyl-3-silyll-propene, 4-cyclohexyl-7(tertiarybutoxydifluorosily)2-dodecene,o-(trimethoysilyl) styrene, odiphenoxysilyl)-p-octylstyrene,o-(benzyloxydichlorosilyl)-omethylstyrene, 3-(tolyloxysilyl)vinylcyclohexane, 3-(tolyloxydibromosilyl)-2-phenyl-l-butene,3-(tripropoxysilyl)-5- methylvinylcyclohexane, 5-cyclohexyl-6-(triethoxysilyl)- l hexene, (methylcyclopentenyl) dichlorosilane.

The reaction of the organo functional groups with the polyolefins isusually catalyzed by a free radical catalyst as for example an organicperoxide or a hydroperoxide such as the following: benzoyl peroxide,tertbutyl hydroperoxide, I- hydroperoxy-lphenylcyclohexane, di (tertiarybutyl) peroxide, methyltetrahydrofuran peroxides, aldehyde and ketoneperoxides, acetyl peroxide, stearyl peroxide, toluyl peroxide, anisylperoxide, cumene hydroperoxide methyl cyclohexyl hydroperoxide,cyclohexyl hydroperoxide, perbenzoic acid, lhydroxycyclohexylhydroperoxide, hydroxy heptyl peroxide, isopropyl (dimethyl)hydroperoxymethane, l-methyl-lhydroperoxycyclopentane, tetralinhydroperoxide, oc-

tahydrophenanthrene hydroperoxide, dimethyl (isopropylphenyl)hydroperoxymethane, methylethyl (ethoxyphenyl) hydroperoxymethane,methyldecyl (methylphenyl) hydroperoxymethane,dimethyldecylhydroperoxymethane,methylchlorophenylphenylhydroperoxymethane, and dimethyl(tertiarybutylphenyl) hydroperoxymethane.

As previously stated, silane hydrogen can also react with the remainingunsaturate groups of a polyolefin using either a free radical catalyst,as for example one of those given or a hydrogenation catalyst such asplatinum, activated carbon or hexochloroplatinic acid or some otherchloroplatinic acid, etc. Suitable examples of compounds having SiHgroups are: silanes such as monosilane, disilane, trisilane, or mixturesthereof, monochlorosilane, dichlorosilane, trichlorosilane, and organosubstituted silanes thereof, such as methychlorosilane,methyldichlorosilane, dimethylchlorosilane, and higher silanescontaining other aliphatic, cycloaliphatic and/or organic radicalsand/or other halogens; hydroxy-organosilanes such astris-isoamyl-hydroxysilane or diethoxysilane, siloxanes, and organicallysubstituted siloxanes, and the oligomers and polymers thereof, as forexample presilaxone (SH-I 0) methyl-hydrogenpolysiloxane (SiHCl-l 0) andother monomer, molecular, and macromolecular silicon compounds providedthat they contain at least one SiH group. A preferred class oforganosilanes are those in which the organo portion contains nitrogensuch as gamma-aminopropylsilane, garnma-aminopropyldiethoxysilane,gamma'aminopropyldimethoxysilane, bis (betahydroxyethyl)gamma-aminopropylethoxysilane, bis (betahydroxyethyl)gamma-aminopropyldiethoxysilane, maminophenyl-di-ptychsiloxazolidine, N(B amino-ethyl) gamma-aminopropylethoxy silane or a diethoxy-silane, N-phenyl-gamma-aminopropylmethoxysilane or the dimethoxysilane, etc.Organo silanes containing nitrogen increased the affinity for thesurface of the glass fibers, and for this reason are preferred.

It will be apparent that there has been provided a new and improvedmethod of dispersing polyolefins in water as well as new and improvedresin coated glass fibers having improved coupling action withpolyolefin molding resin.

While the invention has been described in considerable detail, I do notwish to be limited to the particular embodiments described, and it is myintention to cover hereby all novel adaptations, modifications, andarrangements thereof which come within the practice of those skilled inthe art to which the invention relates.

lclaim:

1. The method of producing polyolefin compatible glass fiberscomprising: forming particles of the reaction product of an organosilanehaving functional groups reactive with carbon to carbon double bonds anda polyolefin, coating said particles with a polyester resin, dispersingthe polyester resin coated particles in water using a surface activeagent, applying the water dispersion of polyester resin coated'particlesto glass fibers, and drying the dispersion on the fibers.

2. The method of claim 2 including the step of: dispersing the solublereaction product of polyethylenimine and an organosilane in the waterused to disperse said polyester resin coated particles.

3. The method of securing a polyolefin to glass fibers comprising:forming particles of the reaction product of an organosilane havingfunctional groups reactive with carbon to carbon double bonds and apolyolefin, coating said particles with a polyester resin, dispersingthe polyester resin coated particles in water using a surface activeagent, applying the water dispersion of polyester resin coated particlesto glass fibers, drying the dispersion on the fibers, mixing the driedfibers with a polyolefin impregnating resin, and applying sufficientheat and pressure to the mixture to fuse the impregnating resin to thereaction product and the reaction product in turn to said fibers.

4. Glass fibers having a coating thereon comprising. particles of thecombination product of an organosilane having polyester materialcomprises a crosslinkable polyester resin and an unsaturatedcross-linking monomer.

7. The glass fibers of claim 4 wherein said polyolefin is polypropylene,and said organosilane is gamma-aminopropyltriethoxysilane.

8. The coated glass fibers of claim 4 wherein said aqueous dispersingagent includes a reaction product of polyethylenimine and anorganosilane.

9. The coated glass fibers of claim 8 wherein said aqueous dispersingagent includes a nonionic emulsifying agent.

2. The method of claim 2 including the step of: dispersing the solublereaction product of polyethylenimine and an organosilane in the waterused to disperse said polyester resin coated particles.
 3. The method ofsecuring a polyolefin to glass fibers comprising: forming particles ofthe reaction product of an organosilane having functional groupsreactive with carbon to carbon double bonds and a polyolefin, coatingsaid particles with a polyester resin, dispersing the polyester resincoated particles in water using a surface active agent, applying thewater dispersion of polyester resin coated particles to glass fibers,drying the dispersion on the fibers, mixing the dried fibers with apolyolefin impregnating resin, and applying sufficient heat and pressureto the mixture to fuse the impregnating resin to the reaction productand the reaction product in turn to said fibers.
 4. Glass fibers havinga coating thereon comprising: particles of the combination product of anorganosilane having functional groups reactive with carbon to carbondouble bonds and a polyolefin, said particles having a coating of afusable polyester resin material thereon, and said fusable polyesterresin coated particles having an aqueous dispersing agent on the surfaceof the polyester resin coating.
 5. The coated glass fibers of claim 4wherein said combination product particles comprise approximately fourparts of polyolefin and approximately one part organosilane, and saidcoating comprises approximately 45 parts of the polyester resin.
 6. Thecoated glass fibers of claim 4 wherein said fusable polyester materialcomprises a crosslinkable polyester resin and an unsaturatedcross-linking monomer.
 7. The glass fibers of claim 4 wherein saidpolyolefin is polypropylene, and said organosilane isgamma-aminopropyltriethoxysilane.
 8. The coated glass fibers of claim 4wherein said aqueous dispersing agent includes a reaction product ofpolyethylenimine and an organosilane.
 9. The coated glass fibers ofclaim 8 wherein said aqueous dispersing agent includes a nonionicemulsifying agent.